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Since the first description of subarachnoid anesthesia by Bier, it has
remained the simplest and most effective technique of regional anesthesia.
The use of neuraxial techniques in outpatients has been a more recent
development, awaiting ready availability of newer needles that reduced the
side effect of postdural puncture headache to an acceptable level in the
ambulatory setting. The last 10 years have seen a dramatic increase in the
use of these techniques in outpatients, for several reasons.
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Simplicity and effectiveness should make central neuraxial techniques
(either spinal or epidural) ideal in the outpatient setting. Both spinal and
epidural anesthesia are more familiar to practitioners than peripheral nerve
blocks and are easier to perform because they do not require nerve
localization techniques. They can be performed rapidly and without
assistance. Neuraxial techniques are effective for lower abdominal,
perineal, and lower extremity surgery, and are among the best choices for
practitioners who are just starting to incorporate regional anesthetic
techniques in an outpatient practice. They also provide optimal outcomes in
most of the important aspects of outpatient anesthesia. Patients with
neuraxial blocks have lower pain scores on admission to PACU than patients
receiving general anesthesia (GA).1–5 Their frequency of
postoperative nausea and vomiting (PONV) appears to be at most one-third of
that after GA.6 Most importantly, the frequency of phase 1
PACU bypass is high,1,6,7 and discharge times are
comparable to even the fastest for GA techniques if appropriate local
anesthetic agents and dosages are chosen.8 Modern
small-gauge rounded point needles and short-acting drugs have reduced the
side effects that were of concern in the past. With propofol infusions
available to provide light but transient sedation, the objection to “being
awake” during regional techniques has also disappeared, leaving neuraxial
techniques as an excellent choice.
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This chapter will focus on the advantages, disadvantages, and practical
points associated with spinal and epidural anesthesia in the outpatient
setting.
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Spinal anesthesia (SA) is one of the simplest and most reliable of
regional anesthesia techniques. The external anatomic landmarks are easily
identified. The block can be performed with minimal discomfort, the
end-point of cerebrospinal fluid flow is unmistakable, and the onset of
anesthesia is more rapid than with any other regional technique. Because of
the rapidity of onset, the block can be performed in the operating room
without the requirement for additional personnel or a block room. The
efficient performance of the block does not add substantially to operating
room time any more than for the induction of GA. The onset of the sensory
blockade is sufficiently rapid to attain surgical anesthesia by the time the
positioning and preparation of the patient are completed. A variety of local
anesthetic agents are available that can provide a wide range of duration of
surgical anesthesia. The risk of nausea can be reduced if systemic opioids
are avoided. Likewise, ...